For example, the "Windows Photo Viewer" in Windows 7 has been totally castrated. In the Vista version, you could view photos and perform simple modifications: rename (from DSC_0216.jpg to MakingAGoofyFace.jpg for example while looking at that picture), fix red eye, crop picture.
All the editing features save rotation have been removed in the Windows 7 version. They didn't even included the simple ability to rename a picture.
To get these standard Vista features back you need to download the "Live Essentials Photo Gallery" which installs all sorts of fun stuff like an SQL Server CE 3.1, MS Application Error Reporting Service, Windows Live Sync, and Windows Live Communications Platform.
Basically, in order to get back a small number of useful features, you need to install the entire "Live" platform of cruftware. Not to mention that the install of the new "Live Essentials Photo Gallery" requires 56MB of diskspace !!!!
I wonder why they didn't leave the simple basic functionality in the original viewer rather than making you have to download an entire "Live Essential" Platform to get a poor Picassa clone.